This invention relates to instrumentation for invading body canals non-destructively and with a minimum of trauma, and more particularly it relates to the interface between the instruments and body tissue during dynamic ingress and egress of surgical instrumentation into the canals.
It has been the direction of the prior art to fashion surface structure of instrumentation for non-destructive invasion of body canals with very slippery surface structure to facilitate ingress and this accordingly produces low friction upon egress.
In the parent application, which is incorporated herein in entirety by reference, however it is disclosed that the ingress of the instrumentation into a desired body site has been facilitated by introduction of novel instrumentation surface structure having a bi-directional coefficient of friction with engaged tissue within the cavities and canals that they navigate. In this manner the naturally occurring peristalatic contractions may advantageously grasp and carry the instrumentation toward its desired work site, significantly decreasing the risks of puncture and significantly decreasing the surgeon""s time for entry of instruments to desired work sites in such procedures as small bowel enteroscopy where an endoscope enters the esophagus passing through the stomach to be placed at work sites in the small intestine. Greater friction upon egress is supplied by microscopic or macroscopic surface texture that does not discomfort the patient or inflame the interfacing body tissue upon egress.
Thus, it has been discovered that significant advantages are afforded by such improved instrumentation surfaces with differential surface friction upon ingress and egress. Such advantages are realized, for example, in the surgical process of feeding such instrumentation into the tortuous, angulated and loosely fixated structures of the body tissue along the body canals through which the instrumentation must be fed. For example, in the case of small bowel enteroscopy an endoscope is fed from the esophagus and through the stomach into the intestines where the distal end must be manipulated to confront curves and folds in the small intestine and corresponding changes in travel direction. With the bi-directional coefficient of friction provided by this invention, the natural peristaltic waves of the body that carry food through this path are engaged to more easily find and traverse the right path through the stomach and the curves and folds of the intestines. It would be impossible to use the peristaltic waves with the slipperiness of the conventional instrumentation of the prior art which has the same coefficient of friction in ingress and egress directions.
The instrumentation to which this invention is directed comprises catheters, guide wires and medical instruments generally employed for dynamic movement into and out of body canals to internal body work sites, which are also employed at times for inspection of the condition of the canals. The modified instrumentation surfaces of this invention thus function in the dynamic ingress and egress through body canals. Thus, the surface structure is fashioned to expedite dynamic entry and withdrawal as distinguished for example from held in position stents providing the stent device with anchoring barbs resisting egress, typically shown in R. P. Gibbons U.S. Pat. No. 3,938,529, wherein the barbs resist movement of the stent both inwardly and outwardly and to avoid damage to body tissue and discomfort of the patient require for the stent to be confined during insertion and inserted through a cystoscope or like instrument into the work site wherein the barbs firmly engage the body tissue lock the stent into a permanent resident and stationary internal body position.
Accordingly it is an objective of this invention to provide improved medical devices for dynamic entry into work sites along body canals to support corresponding improved surgical methods facilitating the ingress of body intrusion instrumentation to those worksites and egress retrieval therefrom without trauma or inflammation of the canal body tissue interfacing with the inserted instrumentation.
A more specific objective of this invention is to provide preferred embodiments of the instrumentation surface structure provided by this invention with differential surface friction characteristics in the ingress and egress directions of movement of such character that trauma and inflammation of the canal body tissue is avoided during the dynamic movements.
Body invasion instrumentation afforded by this invention for ingress and egress into and out of body canals toward internal work sites must be manipulated with little inflammation and discomfort to body tissue at the interface between the instruments and body tissue during ingress and egress of the instrumentation. For this reason the prior art has introduced ways to make surfaces of such instrumentation slippier to avoid any improved kind of barbs or roughness. However this invention relates explicitly to improved methods of surgical exploration in inserting the instrumentation that reduces the need for probing which could inflame or puncture the canal walls. Thus, the instrumentation counters that trend to make instrumentation surfaces slipperier to the extent of providing modified instrumentation surfaces that have a differential friction upon ingress and egress.
The structure for achieving the differential friction property employs microscopic or macroscopic sized surface texture patterns that may be inserted and removed from internal body worksites with little discomfort or inflammation of interfacing body tissue. The preferred structures provide appropriate non-toxic materials of desirable flexibility to navigate body canals with tortuous and angulated paths thereby to withstand the scrutiny of good medical practice and sterility. The instrumentation includes some throw away after single use instruments such as guide wires and catheters as well as instruments that need to be sterilized and reused such as endoscopes. In general it has been found that certain plastics with treated exterior surfaces for providing bi-directional texture are advantageous, and that removable adhesive tapes or elastic sheaths may be disposably used for endoscopes, for example.
This leads to significantly improved surgical procedures for ingress into a work site deep inside the body. In particular the surgeon can control movement of the instrumentation into the worksite with the help of peristaltic propagation normally exerted by the patient""s body. Thus, the differential surface friction feature will cause the instrumentation to naturally flow along the body canals and cavities such as the stomach to navigate desired openings such as the duodenum and small or large intestines, to facilitate movement along tortuous, angulated and loosely fixated body tissue paths. This decreases the possibility of puncture, and saves a considerable amount of the time a surgeon employs in manipulating the instrumentation to an interior body worksite.
Preferred embodiments of producing the bidirectional coefficient of surface friction upon the instrumentation surface are presented with features that facilitate surgical manipulation of the instrumentation and improve the surgeon""s proficiency. The instrumentation is of the type including catheters, guide wires or cables, endoscopes and other associated instruments for performing medical and surgical procedures at internal body worksites.
Other features, objects and advantages of this invention will be found throughout the following description and claims and in the appended drawings.